as in treacherous
formal
causing harm in a way that is gradual or not easily noticed
Most people with this insidious disease have no idea that they are infected. an insidious enemy
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Recent Examples of insidious
In the face of the insidious chaos of 2026, the band rises to the moment with A Wave That Will Never Break, an ecstatic, devotional album stocked with powerful choruses that reflect on the nature of destruction.
—
Nina Corcoran, Pitchfork, 23 Mar. 2026
The work of documentaries must be rigorous, contextualized, and unflinching enough to help stop the progression of an insidious message and movement.
—Alison Foreman, IndieWire, 19 Mar. 2026
The show, which runs through March 28, has a blistering message to impart about the insidious nature of authoritarian political movements and the dangers of being oblivious or indifferent.
—Christopher Arnott, Hartford Courant, 18 Mar. 2026
But the kind of harassment that may not rise to the level of a crime in most countries – more pervasive and more subtle, but nonetheless insidious – has largely remained unacknowledged in Brazilian jiu-jitsu.
—Ina Seethaler, The Conversation, 4 Mar. 2026
See All Example Sentences for insidious
Nina Corcoran, Pitchfork, 23 Mar. 2026
The work of documentaries must be rigorous, contextualized, and unflinching enough to help stop the progression of an insidious message and movement.
—Alison Foreman, IndieWire, 19 Mar. 2026
The show, which runs through March 28, has a blistering message to impart about the insidious nature of authoritarian political movements and the dangers of being oblivious or indifferent.
—Christopher Arnott, Hartford Courant, 18 Mar. 2026
But the kind of harassment that may not rise to the level of a crime in most countries – more pervasive and more subtle, but nonetheless insidious – has largely remained unacknowledged in Brazilian jiu-jitsu.
—Ina Seethaler, The Conversation, 4 Mar. 2026
See All Example Sentences for insidious
Recent Examples of Synonyms for insidious
Adjective
-
After navigating the treacherous play-in round the past three years to make it to the playoffs, and even the NBA Finals in 2023, the Heat’s run of six consecutive seasons in the playoffs is over.—
Ira Winderman,
Sun Sentinel,
15 Apr. 2026
-
For truckers, that stretch of New Orleans East had become an asphalt Bermuda Triangle—a treacherous gantlet best avoided.—
Patrick Radden Keefe,
New Yorker,
13 Apr. 2026
Adjective
-
Custom metallic-textile curtains are used to help filter light and protect sensitive works, while allowing subtle changes throughout the day and seasons to shape the viewing experience.—
City News Service,
Daily News,
16 Apr. 2026
-
While Drescher used the Pink Passion shade, there are five other colors to pick from, including a timeless bright red and subtle neutral hue.—
Rylee Johnston,
PEOPLE,
16 Apr. 2026
Adjective
-
For me, the possible false note lay not in Aramayo’s performance but in the script.—
Justin Chang,
New Yorker,
17 Apr. 2026
-
Local police too, have stated that false posts circulating in WhatsApp groups, including claims of worker deaths and exaggerated reports of violence and arrests, have contributed to the escalation of unrest.—
Mayu Saini,
Footwear News,
17 Apr. 2026
Adjective
-
There is a relaxing vibe about Hilton Head, and a lot of wedges in the hands of the best players, both of which can be deceptive.—
ABC News,
ABC News,
15 Apr. 2026
-
Anything else amounts to a deceptive user experience that can discourage users from visiting unfamiliar pages in the future.—
ArsTechnica,
ArsTechnica,
14 Apr. 2026
Adjective
-
The government took a genuine invitation to collaborate as a perfidious power grab.—
Gideon Lewis-Kraus,
New Yorker,
14 Mar. 2026
-
For those trying to read Iran’s future, the lesson of 1953 is not just that foreign powers can be perfidious.—
Bobby Ghosh,
Time,
5 Mar. 2026
Adjective
-
County officials also said Freidenrich’s management of the treasurer’s office led to delays in issuing refunds to schools, filing tax liens and cashing property tax checks, which resulted in incorrect late fees and penalties for taxpayers.—
Claire Wang,
Oc Register,
15 Apr. 2026
-
Any assertion that city single-family homeowners are being double taxed would be incorrect.—
U T Readers,
San Diego Union-Tribune,
13 Apr. 2026
Adjective
-
Now 43-38, Charlotte has lost ground this week with difficult losses to Boston and Detroit that followed the same blueprint, as the Hornets fell off a cliff in the fourth quarter at the wrong time.—
Scott Fowler,
Charlotte Observer,
11 Apr. 2026
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Overfertilizing Fertilizing too much or at the wrong time could potentially damage plant roots, leading to leaf damage and eventual drop.—
Alexandra Jones,
The Spruce,
11 Apr. 2026
Cite this Entry
“Insidious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/insidious. Accessed 22 Apr. 2026.
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